This subtitle applies to: A fiduciary acting under a will or power of attorney executed before, on, or after October 1, 2016; A personal representative acting for a decedent who died before, on, or after October 1, 2016; A guardianship proceeding, whether pending in a court or commenced before, on, or after October 1, 2016; A trustee acting under a trust created before, on, or after October 1, 2016; and A custodian if the user resides in this State or resided in this State at the time of the user’s death.